Ping! The sonar continued its never ending beat. Waves of powerful but invisible sound pounded the black ocean waters in a futile attempt to hear the enemy. A propeller, a turbine or even a cough were all that they needed to catch the mouse. A whisper of sound and the chase would begin. The mouse was no fool. It would not let out so much as a squeak to give the cat the thrill of the hunt. It would bide its time in the shadows of the deep blue grotto until the cat succumbed to boredom and left it well enough alone. "They're s ....